Some Basic Aspects of the Triple Decomposition of the Relative Motion near a Point

The triple decomposition of the relative motion near a point (TDM) ― based on the extraction of a so-called “effective” pure shearing motion ― has been recently proposed by the present author. The relative motion near a point has been decomposed through the analysis of a “frozen” flow field at a given instant in time. This approach has been motivated by the fact that vorticity cannot distinguish between pure shearing motions and the actual swirling motion of a vortex. The TDM results in two additive vorticity parts and two additive strainrate parts of distinct nature: the shear component associated with a pure shearing motion and the residual one. Some basic aspects of this novel decomposition technique are treated in the present paper. These aspects include: pure shearing motion and shearing elements in 3D, orbital compactness vs. arbitrary axial strain of a vortex, the interpretation of residual vorticity and the concept of residual circulation (i.e. a surface quadrature of the residual vorticity) for the description of vortex strength, and qualitative comparison of the TDM vorticity outcome with other known vorticity-decomposition techniques

GS-trapezoids in GS-quasigroups

In this paper the concept of a GS-trapezoid in a GS-quasigroup is defined and some characterizations of that are proved and geometrical representation of the properties of the quaternary relation GST in the GS-quasigroup $C(frac{1}{2}(1+sqrt{5}))$ is given

Metrical relationships in a standard triangle in an isotropic plane

Each allowable triangle of an isotropic plane can be set in a standard position, in which it is possible to prove geometric properties analytically in a simplified and easier way by means of the algebraic theory developed in this paper

DGS-trapezoids in GS-quasigroups

The concept of the DGS-trapezoid is defined and investigated in any GS-quasigroup and geometrical interpretation in the GS-quasigroup $C( frac{1}{2}(1+sqrt 5 ))$ is also given. The connection of this concept with GS-trapezoids in the general GS-quasigroup is obtained

GS-deltoids in GS-quasigroups

A "geometric\u27\u27 concept of the GS-deltoid is introduced and investigated in the general GS-quasigroup and geometrical interpretation in the GS-quasigroup $C( frac{1}{2}(1+sqrt 5 ))$ is given. The connection of GS-deltoids with parallelograms, GS-trapezoids, DGS-trapezoids and affine regular pentagons in the general GS-quasigroup is obtained

Stammler\u27s circles, Stammler\u27s triangle and Morley\u27s triangle of a given triangle

By means of complex coordinates shorter proofs of the results of L. Stammler [1], [2] will be given, plus several statements connected with them

Conforming finite element methods for the clamped plate problem

Finite element methods for solving biharmonic boundary value problems are considered. The particular problem discussed is that of a clamped thin plate. This problem is reformulated in a weak, form in the Sobolev space Techniques for setting up conforming trial Functions are utilized in a Galerkin technique to produce finite element solutions. The shortcomings of various trial function formulations are discussed, and a macro—element approach to local mesh refinement using rectangular elements is given

The influence of air pollution on the content of 3.4-benzpyrene in nonrefined oil obtained from sunflower seeds grown in differently polluted areas

Postavljena je pretpostavka da je zagađenost zraka jedan od bitnih elemenata koji uslovljuju kontaminaciju biljnih ulja. Određivan je sadržaj 3,4-benzpirena u sirovom suncokretovom ulju, ekstrahiranom iz sjemena suncokreta, uzgajanog na različito kontaminiranim područjima, kao i u uzorcima zemlje, uzetih sa zasijanih površina. Isključeni su moguće utjecaji u periodu sazrijevanja sjemena (žetva, transport, skladištenje) pa do finalne industrijske prerade. Uzorci sjemena su ručno sabrani i laboratorijskom tehnikom priređeni uzorci ulja. Nađene količine 3,4-benzpirena u ulju, u količinama od 0,4-40,5 µg/kg ulja, pokazuju direktnu ovisnost o intenzitetu zagađivanja zraka. Relativno visoki sadržaj 3,4-benzpirena u uzorcima zemlje (29,3-900,0 µg/kg zemlje) ukazuju na veliku rezistentnost i mogućnost akumulacije ove karcinogene supstance.It is supposed that air pollution is one of crucial factors in contamination of vegetable oils. The content of 3,4-benzpyrene was determined in nonrefined oil, obtained from sunflower seeds which were grown in areas with varying degree of pollution, and in the samples of soil taken from the same areas. Possible influences during the ripening of the seed (harvest, transport, storage) until the final industrial processing were excluded. Seed samples were hand collected and oil samples prepared under laboratory conditions. The amount of 3,4-benzpyrene in oil ranges from 0.4-40,5 µg/kg oil and shows direct relationship with the intensity of air pollution. A relatively high content of 3,4-benzpyrene in soil samples (29.3-900.0 µg/kg soil) points at a high resistance and possibility of accumulation of this carcinogenic substance

Amperometric separation-free immunosensor for real-time environmental monitoring

Immunoanalytical techniques have found widespread use due to the characteristics of specificity and wide applicability for many analytes, from large polymer antigens, to simple haptens, and even single atoms. Electrochemical sensors offer benefits of technical simplicity, speed and convenience via direct transduction to electronic equipment. Together, these two systems offer the possibility of a convenient, ubiquitous assay technique with high selectivity. However, they are still not widely used, mainly due to the complexity of the associated immunoassay methodologies. A separation-free immunoanalytical technique is described here, which has allowed for the analysis of atrazine in real time and in both quasi-equilibrium and stirred batch configurations. It illustrated that determinations as low as 0.13 muM (28 ppb) could be made using equilibrium incubation with an analytical range of 0.1-10 muM. Measurements could be made between 1 and 10 mM within several minutes using a real-time, stirred batch method. This system offers the potential for fast, simple, cost-effective biosensors for the analysis of many substances of environmental, biomedical and pharmaceutical concern. (C) 2001 Elsevier Science B.V. All rights reserved